Control method and control unit for a marine vessel

Abstract

A method to control a marine vessel comprising two or more drive units. The method involves registering an operating command indicating a requested sideways or bow bollard push function; detecting a current vessel position; registering the current vessel position as a desired vessel position; executing the requested bollard push function; and monitoring the current vessel position in order to detect a deviation relative to the desired vessel position. If it is detected that a deviation between the desired vessel position has exceeded a predetermined value, then the requested bollard push function is deactivated. The disclosure further relates to a control unit arranged to control a marine vessel and a marine vessel comprising such a control unit.

The invention claimed is: 
     
       1. A method to control a marine vessel comprising two or more drive units; the method involving the steps of:
 registering an operating command indicating a requested bollard push function; 
 detecting a current vessel position; 
 registering the current vessel position as a desired vessel position; 
 executing the requested bollard push function by controlling thrust and direction of the drive units in order to push the vessel against a fixed structure at a requested heading with a predetermined force; 
 during execution of the requested bollard push function, monitoring the current vessel position in order to detect a deviation relative to the desired vessel position; 
 if the detected deviation relative to the desired vessel position has exceeded a predetermined value, 
 deactivating the requested bollard push function, wherein deactivation of the bollard push function will at least involve an inhibition of the thrust from the drive units. 
 
     
     
       2. The method according to  claim 1 , comprising monitoring if the deviation of a current vessel position relative to the desired vessel position has exceeded a predetermined distance. 
     
     
       3. The method according to  claim 1 , comprising monitoring if the deviation of a current vessel heading relative to the desired vessel heading has exceeded a predetermined angle. 
     
     
       4. The method according to  claim 1 , comprising monitoring if the rate of change of the deviation for a current vessel position relative to the desired vessel position has exceeded a predetermined value. 
     
     
       5. The method according to  claim 1 , comprising registering the bollard push function in response to an input signal from a joystick. 
     
     
       6. The method according to  claim 1 , comprising registering the bollard push function in response to an input signal from a graphical user interface. 
     
     
       7. The method according to  claim 1 , comprising registering the bollard push function in response to input signals from at least one throttle controller and a helm controller. 
     
     
       8. The method according to  claim 1 , comprising disengaging the drive units when deactivating the requested bollard push function. 
     
     
       9. The method according to  claim 1 , comprising the further steps of:
 registering an updated current vessel position; and 
 executing a position hold function in order to maintain the updated current vessel position. 
 
     
     
       10. The method according to  claim 1 , wherein the vessel position is determined by a Global Navigation Satellite System. 
     
     
       11. A non-transitory computer program product comprising program code stored on a computer readable medium for performing the method according to  claim 1  when said program code is run on a computer. 
     
     
       12. A control unit arranged to control a marine vessel comprising two or more propulsion units, the control unit comprising processing circuitry, the processing circuitry being configured to receive an input indicating a requested vessel function, wherein the processing circuitry is configured to:
 register an operating command indicating a requested bollard push function; 
 detect a current vessel position; 
 register the current vessel position as a desired vessel position; 
 execute the requested bollard push function by controlling thrust and direction of the drive units in order to push the vessel against a fixed structure at a requested heading with a predetermined force; 
 during execution of the requested bollard push function, monitor the current vessel position in order to detect a deviation relative to the desired vessel position; 
 if the detected deviation relative to the desired vessel position has exceeded a predetermined value, the processing circuitry is configured to: 
 deactivate the requested bollard push function, wherein deactivation of the bollard push function will at least involve an inhibition of the thrust from the drive units; 
 register an updated current vessel position; and 
 execute a station keeping function in order to maintain the updated current vessel position. 
 
     
     
       13. Marine vessel, wherein the marine vessel comprises a control unit according to  claim 12 .